An amusing notion, but keep in mind where the endpoint for this lies. There's two possible routes, as far as I can see:

First is the Diamond Age route, where the 'bots go smaller and smaller until they get to the nanoscale, and we end up with 'toner' everywhere.

The second is building a spider to catch the fly, building a bird to catch the spider, building a cat to catch the bird, et al., until you get up to the point where you're making little old ladies swallow equines to take care of a surveillance bug.

Maybe a better venue would be to show it at The Museum Of Modern Fascism.

On the other hand, your basic laws of scaling are going to be an effective law to limit the usefulness of these gadgets. The battery power goes down as the cube, while the air resistance is at least one power below that, so they're going to be mighty short-lived, like seconds rather than minutes.

I like this- I've written one of these into a book. I had it powered by a broadcast infrared beam aimed at it, and a character fools with it by blocking the beam, causes it to falter, and then is embarrassed because he was caught interfering with it while it was working:)

If the surveillance culture thing bothers you, keep working on cracker tech so we can always tap into the wireless signal and decode it. Information restriction is going to be impossible. Information parity is where it's at (though it's not going to be a gift- it's probably always going to be a captured prize.) This will tend to create an 'information serf class' which gets lied to by people who are confident they won't be able to sort out the truth.

Keep in mind that another area of research that's getting attention at the moment is broadcast power--so you wouldn't have to have an onboard source, per se, but merely a collector to snag a couple microwatts from the local broadcast basestation. It'll probably take about as long for 'wireless' power like that to become popular as it'll take to develop an effective avionics package for the flybot, so that'll work out nicely.

I am sure the comments will be flooded with alarmists screeching about black helicopter secret governments. I have a different opinion.

I cannot imagine that any truly great surveillance technology (such as tiny robotic flies) won't be used for selfish purposes -- by all layers of American society. You know your manager wants to spy on you, why not spy on your manager if there's no chance of getting caught? Get some nice juicy dirt! Back-room dirty deals among politicians? It's on Youtube now!

It's hard to accept, but we're hurtling toward a privacy-free society, including corporate board-rooms, Congressional meetings, NDAs (forget em), and whatever you do in your garage on Thursday nights.

The expression "I wish I was a fly on the wall when $EVENT happened" is soon to become reality...

Would you believe 20 minutes into the future?

Carter: What I wouldn't give to be a fly on that boardroom wall.Bryce: Well, you can if you like.Carter: What?Cheviot:...got to stop this now!...Carter: Bryce, what is this?Bryce: Oh, it's a bug. Well, a fly, actually. It was my graduation project when I was eleven.Carter: A mechanical fly?

You can call it "crap" all you want - but guess what! This technology is really on its way - is very real and tangible

I'm both an engineer and an R/C heli/airplane fan - and I've been pretty amazed at the kind of stuff that's been coming available over just the last few years - and I'm not talking "scientific research" but even commercial products you can find at your local hobby store or mall.

Lets look:

Batteries Crazy advances in odd things like Li-Po batteries and "supercaps" which are very light, small, and can charge very quickly.

Motors Brushless electric motors with much greater power and efficiency. People are literally ripping their gas engines out of their 60-sized helis and replacing them with electric motors and batteries!

I mentioned in a comment down the page a bit that by the time they get a decent avionics package scaled for the thing, all that broadcast power research that folks keep talking about will have caught on, at least a little bit.

Or perhaps they could take a leaf from that UAV design that was in the news a while ago that would supposedly leech power from distribution lines--a similar idea, but scaled down to fly size. You wouldn't need more than a few microwatts to power a fly, I shouldn't think, and you could probably get that from induction by sitting on a lamp cord or something.